Clamp for concrete forms



Maia-3, 1925'.

v I 15,528,105v J. FROELICH ET AL v CLAMP FOR CONCRETE FORMS Filed March 31, 1924,

Patented Mar. 3, 1 925.

UNITED. STATES PATENT OFFICE.

JOHN FRO-ELICH,' OF ST. PAUL, O-T'IUH. KNOSPE, OF NORTH ST. PAUL, AND ADOLPH ST. PAUL, MINNESOTA.

cLAMPfFon cononn'rn Forms.

Application filed March 31, 1924. Serial Nb.- 703,045.

To all whom it mayc'oncemi'z Be it. known that we, JOHN .Fnonmcn,

Or'ro H. KNOSPE, and=ADoL1 H.E. Errmcs HAM, residents of St. Paul, North St.-Paul, andSt. Paul, respectively, in the county of Ramsey and. State of Minnesota, have in' vented-new and usefullmprovements in a Clamp for Concrete Forms, of which the following-Vis a specification.

This invention relates tOclainpsfQr con.- creteiorms, particularly, although not exclusively, adapted for use in the'constructionofcolumns. Q

Heretofore,.the devices provided-for this purpose. have required an excessive amount of handlaborpin the erection of the forms, and do not permit sufiiciently accurate adj ustment to fit forms of differing shapes and sizes. Furthermore, as-tar as applicants, are aware, in all of the common types of form clamps'the angles at the corners of the columns are to a certain extent at least. changeable and dependent upon the estimate of :the workmen for their exactness, so that colum-nsarefrequently constructed having. un

equal or incorrect angles at the corners.

Itis" our object to obviate these defects by providing an accurately adjustable clamp adapted to securely hold a form in correct position, while permitting quick and: easy attachment and-removal, from the forms. Our invention also includes certain other novel features of construction which will appear and be-inore-fullypointed out in the following specification andclaims. 7

Referring to the accompanying drawings, which illustrate the best form ofour device at present known to us, Figure 1" is a perspective view of our clamp mounted on a tonnof common type; Fig. 2-is a plan View showing the bar which engages two sides of the form, together with the device for holding the ends of'said bar in proper relation with a companion bar, one of the ,holders being shown in horizontal section; Fig. 3 is a plan view showing the rigid corner of the companion bar and adjacent parts of theinvention; Fig. 4 is a detail perspective View of one of the corner holders, and Fig. 5 is an inside elevation of the same.

In the drawings, we: have used the numerals 6 and 7 to indicate the pair of bars adapted to form a polygon about-a concrete for1n 8. Each ofithe bars 6 and 7 comprises two straight portions rigidly connected at the corners 9. and 10, respectively and the ends of said hars cross to ,form a rectangle. The crossed ends of the bars 6 and 7 are slidably joined byholders 11, each compris ing a pair of similar plates 12 connected by L; shaped guides 18, and carrying between their adjacent faces a roller 14, journaled on a pin 15' which is fixed in the plates 12. Each. of the holders 11 is formed with an aperture 16 adapted to loosely receive an end of the bar 6, while a guide way 17 is provided beneath said aperture-to slidably receive the co npanion bar 'Z. This guide way 17 is open. at one edge to permit the holder to be moved longitudinally on the bar 6 out ofengageinent with the bar 7; Fixed in each 'end of the bar 6 is a pin 18 arranged to prevent one of the holders 11 from sliding ofi, the endof the bar 6. j

A" chain 19 passes around the form 8 and is connected near its-ends tothe bar 6 by a pair'of pins 20 which project through links of, said chain. bar. 7 near the corner of the form 8 opposite the pins20 is a pair of triangular plates 22, to the outer corners of which, a turnbuckle 23 and rod 24 are connected. The turnrbuckle 23 and rod 24 are disposed in continuation of. the chain 19, being severally joined to said chain and to pins 25. and 26, respectively, fixed in the plates 22. Thus, as.,will be readily understood, tension in the chain 19 may be adjusted by manipulating the turn-buckle 23, and the rollers 14; permit free movement of the chain uponthe holders 11. x

In constructing a column, the form 8 is first built inthe usual manner and is properly squared and clamped in place by the application of our invention. To apply the clamp, the bars 6. and 7, are first placed about the form 8 'with the ends of said bars crossed, as shown in Figure 1.- The holders 11 are now moved on the bar 6 into engagement with the bar 7 and secured in place by the chain 19. To attach the chain 19 to the bar 6,said chain is first placed between the Secured by a pin 21 to the I plates 12 of the holders 11 upon the outer peripheries of the rollers 14, and the pins 20 are inserted through a pair of the chain links as far from the ends of said chain as possible. By means of the turn-buckle 23, the chain is finally drawn tight so as to press the bars 6 and 7 firmly upon the outer surfaces of the-form 8.

By reason of the fixed angles at the corners 9 and 10 of the clamp and the arrangement of the guide angles 13 in the holders 11, the clamp tends to produce a perfect rectangle when the chain 19 is tightened. On account of the simplicity of our device, it can be quickly and easily attached and removed from the form by a single workman.

lVhile we have illustrated a clamp for a rectangular column, it will be evident that where desired the bars 6 and 7 may be formed with other angles, such as where hexagonal or octagonal columns are required, and any such change in the angles or number of sides of the polygon produced by the clamp is considered Within the scope of our invention. A wire cable or other flexible retaining means might also be substituted for the chain 19, without departing from the spirit of our invention. Furthermore. while we prefer to make at least two fixed angles in the clamp, such as those shown at the corners 9 and 10, it will be obvious that some of the advantages of our. invention mightbe secured by providing a pivotal connection between the bars at such corners.

Having described our invention what we claim as new and desire to protect by Letters Patent is:

1. In a device of the class described, a rigid bar adapted to confine at least two sides of a polygonal concrete form, a companion bar adapted to confine the remain ing sides of said form, the ends of one of said bars being arranged to cross the ends of the other bar, holders for the crossed ends of said bars, flexible means connected to said bars and at least partially encircling said form, and means adapted to be manipulated to increase the tension in said flexible means to thereby press said bars upon said form.

2. In a device of the class described, a rigid bar adapted to confine two sides of a rectangular concrete form, a companion bar adapted to confine the remaining sides of said form, the ends of one of said bars being arranged to cross the end of the other bar, holders at the junction of the crossed ends of said bars, flexible means at least partially encircling said bars and holders and arranged to press said bars upon said form, and means adapted to be manipulated to increase or decrease the tension in said flexible means.

3. In a clamp of the class described, a

plurality of bars adapted to conform to the outer surface of a concrete form, certain of the ends of said bars being slidably connected to adapt the clamp to fit forms of differing sizes, a chain adjustably secured near its ends to said bars and disposed to at least partially encircle said form, means for tightening said chain, and means disposed between said chain and bars whereby said bars will be pressed upon said form when said chain is tightened.

4. In a clamp of the class described, a plurality of bars adapted to bear upon the outer surfaces of a concrete form, the ends of certain of said bars being slidably connected to adapt the clamp to fit forms of differing sizes, flexible retaining means connected to said bars and disposed to partially encircle said form, means for drawing said retaining means tight about said form and holders disposed between said retaining means and bars whereby said bars will be pressed upon said form when said means are tightened.

5. In a clamp of the class described, plurality of bars severally adapted to bear upon the sides of a polygonal concrete form, the ends of certain of said bars being slidably connected to adapt the clamp to fit forms of differing sizes, a chain connected near its ends to said bars and disposed to encircle said form, means for adjusting the tension in said chain, and means disposed between said chains and bars whereby said bars will be pressed upon said form when 100 said chain is tightened.

6. In a device of the class described, a plurality of bars adapted to bear upon the sides of a polygonal concrete form, the ends of one of said bars being arranged to cross 106 the ends of another bar, a holder for the closed ends of said bars slidable thereon, flexible means in engagement with said bars and holder, adapted to press said bars upon said form, and means adapted to be manipu- 110 lated to increase or decrease the tension in said flexible means.

7. In a clamp of the class described, a rigid bar adapted to bear upon two sides of a rectangular concrete form, a companion 115 bar disposed to bear upon the opposite sides of said form, the ends of one of said bars being arranged to cross the ends of the other bar, holders for the crossed ends of said bars slidable thereon near their junc- 120 tion, rollers journaled in said holders between the crossed ends of said bars, and flexible means secured to said bars and guided upon said rollers whereby said bars may be held in engagement with said form. 125

' 8. In a clamp of the class described, a rigid bar adapted to bear upon a plurality of sides of a polygonal concrete form, a companion bar adapted to bear upon the opposite sides ofsaid form, the ends of one of said bars being arranged to cross the buckle disposed in said chain to be manipuends of the other bar, holders for the crossed lated to adjust the tension in said chain. 1 ends of said bars slidable thereon near their In testimony wherof, We have hereunto junction, rollers journaled in said holders signed our names to this specification. between the crossed ends of said bars, a

chain secured to said bars and guided upon JOHN FROELICH.

said rollers whereby said bars may be held OTTOH. KNOSPE.

in engagement With said form, and a turn- ADOLPH EFFINGHAM. 

